Doctor blade holder



Sept. 14, 1954 F. F. KAISER DOCTOR BLADE HOLDER 2 Sheets-Sheet 1 FiledDec. 17, 1952 HIH] Wing;

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ATTORNEYS Sept. 14, 1954 F. F. KAISER 2,688,919

DOCTOR BLADE HOLDER Filed Dec. 17, 1952 2 Sheets-Sheet 2 ATTOR NE Y5Patented Sept. 14, 1954 UNITED STAT S PATENT OFFICE to John Waldron CorN. J., a corporation This invention relates to doctor blade holderassemblies for machines of the intaglio printing type or othersrequiring a quickly removable and separable doctor blade.

It is a general object of thepresent invention to provide a novel andimproved doctor blade holder assembly and more-particularly such anassembly permitting ready and quick removal and replacement of thedoctor blade without the use of tools and facilitating the mounting andadjustment of the blade.

More particularly it is an object of theinvention to provide a doctorblade assembly inwhich the blade and its shears are removable as a unitfrom the supporting fulcrum's and flexing adjusters by a mere liftingaction.

An important object of the invention comprises the arrangement on theends of the blade shears of saddle plates involving hooks and notchescapable of assuming and holding fixed positions on rotatably adjustablepin bars cooperating with blade flexing means.

Another important object of the invention resides in the interlocking ofthe saddle plates and pin bars to permit ready assembly and'disassemblywhile providing for longitudinal'vibrationof the blade to preventstreaking, etc;

Features of novelty include:

Mounting of saddle plates on overhanging ends of upper shear bar;

suspending whole doctor assembly between end plates;

Attachment of flexing adjusters -to rocking pin bar from which bladeshear unit is quickly detachable; and

Particular arrangement of hooks and notches on saddle plates.

Other and further objects and features of the invention will be clear tothose skilled in the art from a consideration of the followingspecification and accompanying drawings wherein is disclosed a singleexemplary embodiment of the invention, with the understanding that suchchanges may be madetherein as fall within-the scope of the appendedclaims without departing from the spirit of the invention.

In said drawings:

Fig. 1 is a fragmentary endelevation of a multi-color printing machineequipped with a doctor holder assembly constructed in accord ance withthe present invention, parts not directly relevant to the inventionbeing'sh'ownin dot and dash lines;

Fig. 2 is a transverse section through" the doctor-blade and bladeshearsan'd the ihta'glio poration, New Brunswick,

of N ew Jersey Application December 17, 1952, SerialNo. 326,545 9Claims. (Cl. 101-157) 2. printing roll showing the doctor holder andblade flexing adjusting screw;

Fig. 3 is an elevation of the doctor holder assembly and associatedparts at one end thereof;

Fig. 4 is a top plan view thereof; and

Fig. 5 is an exploded perspective view of the parts forming one end ofthe doctor holder assembly.

Invarious forms of paper converting machines, and notably intaglioprinting machines, use is made of a thin, flexible steel blade known asa doctor either for controlling the thickness of a coating substancesuch as coloring material or the like on the surface of an applyingroller, or for removing ink from the polished cylindrical surface of anintaglio roll and leaving only that required for printing in theengraved depressions inthe roll. Whatever the purpose and however used,there is a considerable need and demand for a readily removable doctorblade since often during its use it must be removed for cleaning or thelike. The blade must be rigidly mounted and conveniently adjustable tochange its flexing and hence the'pressure with which it bears on thesurface ofthe roll. It is therefore highly desirablev that the doctorblade and its supporting shears be readily removable without the use of.tools or actually without the disconnecting of any parts, so that it canbe lifted quickly from the machine, cleaned and restored to its originalposition without adjustments. The manner of mounting also is preferablysuch that longitudinalreciprocation or vibration within limited rangemay be given to the doctor so as to prevent streaking or the like on thesurface of the roll being cleaned by it. Such vibration alsoprevents'undue wear on those portions of the edge of the doctor bladewhich pass over the engraving on the roll.

For convenience the inventoin has been disclosed'in connection with amulti-color printing machine of the rotary impression cylinder type suchas might be used for web printing of fabrics, plastics, wall paper andthe like, but it will be understood that this use of the invention iswholly illustrative and in no sense limiting.

For a better understanding of the drawing reference should now be had toFig. 1, which is a fragmentary side elevation of a rotary type printingmachine for multi-color work. At It there is seen a portion of theperiphery of the rotary impresion cylinder around'which the web to'be'printed is passed; It is supported from and journalled on suitable sideframes, not shown, which mount a plurality of substantially or printingroll whose impression cylinder ranged on the mounting ways I I.

i of a sharp edged,

are adjustably mounted the various inking and printing assemblies, oneof which is illustrated in the drawing. At I2 is seen the engravedintaglio periphery contacts the web running on the surface of theimpression cylinder A gear driven in unison with the engages with theidler gear l3 which in turn meshes with gear l4 secured to the intaglioroll for driving it at the same peripheral speed as the impressioncylinder.

Ink is delivered to the whole surface of the 1 intaglio roll in excessquantity by means of the furnish roll 15, shown in driving contact withthe periphery of the intaglio roll. This furnish roll has its lowerportion immersed in ink in the fountain it removably and adjustably ar-A quantity of ink is picked up by the furnish roll and delivered to thesurface of the intaglio roll which rotates j in a counterclockwisedirection as viewed in Fig.

l. The ink not only fills in the depressions or engravings in the rollsurface but also covers the high polished, smooth periphery thereof,

j from which it must be wiped so that no smudging of the white areas ofthe web being printed will take place, and this is achieved by the usethin, flexible steel doctor blade ll bearing on the periphery of theintaglio roll between the positions where it contacts the furnish rolland the impression cylinder.

With a number of inking and printing systems arranged about theperiphery of the impression cylinder, a varied assortment ofarrangements of the furnish roll and the intaglio roll are needed inorder that the furnish roll may always dip in an open ink fountain forthe proper supply of this liquid. This requires somewhat differentdispositions of the furnish roll and the doctor blade in order tocompensate for the different orientation of the various parts, but ineffect the final results are always the same. The various rolls aresuitably journalled as shown in bearings carried by the radial arms i Iin the manner which forms no part of the present invention.

The two ends of the machine are identical and for convenience but asingle one has been shown.

As seen in Figs. 3 and 4 side members l8 are slidably arranged on theradial arms H and adjustable to be moved in accordance with therequirements fixed by the diameter of the intaglio roll, which is madeinterchangeable for the purpose of varying the style and length ofrepeats of the pattern of the material printed. Each side member i8 hasrigidly secured thereto, as by screws and dowel pins received in theopenings shown in Fig. 5, an end plate 20 of the gen eral configurationseen in Figs. 2 and 5. The exact shape of this plate will depend on thedisposition of the particular inking mechanism about the impressioncylinder. This end plate has secured thereto and extending normal fromits face a fulcrum or journal cylinder 2| and at a suitable spaceddistance therefrom the sleeve 22. A collar 23 on cylinder 2! reinforcesits connection to the plate and forms an abutment.

A pin bar 24, best seen in Fig. 5, comprises a rectangular block 26having extending from one face thereof a pair of large diameter parallelpins 21 and 28. Between these pins and on an axis parallel to theirs isprovided a bearing opening 29 of a diameter to have a close working fitover the journal cylinder 2! on end plate 20. Secured transversely tothe pin bar block on the opposite face from the pins and extendingupwardly therefrom, is the adjusting lever 30. This has on its outerface the spacer bushing 3| which is drilled to the same diameter as theopening 29 to provide an elongated bearing for the block on the cylinder2|, which is sufficiently longer than the overall length of opening 29to be provided with a peripheral groove 32 near its outer end to receivea washer or snap ring 34 for the purpose of holding the parts in theirassembled relation. The block is well spaced from plate 20 by collar 23and bushing 3!.

Near its outer end each adjustment lever 30 is provided with a bore 35parallel to the bearing opening 29 and which receives with a working fitthe integral trunnion 36 extending from a block 3'! having a threadedtransverse bore 38 adapted to receive the screw 39 whose unthreadedshank portion is journalled in a stud block 40 having a tranversebearing in 4! adapted to be received in a bore 42 of sleeve 22 on endplate 28. A large knurled head .43 facilitates manipulation of the screwand a collar 44 thereon prevents longitudinal movement of. the screwshank in stud Ml, the other end of the stud being engaged by the base ofthe screw head.

. It will be appreciated that the arrangement just described permits ofrocking the pin bars about their coaxial journal pins 2i with a fineadjustment by manipulation of the large knurled knobs 43 on theadjusting screws. In this manner the doctor blade may be adjusted towardor into contact with the surface of the printing roll and given anydesired degree of flexing to increase its pressure thereon. Because ofthe flexibility of the doctor blade assembly itself, slight variationsin the pressure exerted by its opposite ends may be achieved because ofthe separate adjusting screws.

As previouslymentioned, the doctor blade itself, numbered ll in thedrawings, is a relatively thin sheet of hard, spring-tempered steel ofconsiderable width and of such thickness that it has the desiredflexibility and capability of following the surface of the printing rollclosely enough to clean it completely of any residual ink. Itscontacting edge is for this purpose carefully ground to considerablethinness. To impart the desired longitudinal rigidity and stiffness tothe blades its rear portion only is mounted between a pair of shearbars, the lower one being of approximately the same length as the bladeitself, whereas the upper shear bar 5| extends beyond the blade ends asclearly seen in Figs. 3 and 4. The three parts are secured together inan appropriate manner, not shown, as forinstance byscrews whose shankspass freely through appropriate openings in the blade and one shear barand whose threaded ends are received in aligned openings in the othershear bar. Beneath each over hanging end of the upper shear bar issecured a saddle plate 52, as best seen in Figs. 3, 4 and 5 These saddleplates are irregular shaped steel plates of substantial thickness havinga width and length substantially corresponding to that of the pin faceof block 26 forming the major portion of the pin bar. Their upper edgesare drilled and threaded as shown at 53 and correspondingly spacedunthreaded apertures 54 are placed. in the ends of the upper shear barto receive screws 55 for cooperation between the saddle. blocks. and thepin bar, now about to be described.

During its construction each saddle plate. is providedawiththroughaperturesv corresponding in size, positioning and arrangement to the.corresponding pins 2.-1 and: 28 in the pin bar. The one of these 56 nearthe rear oftheblade assembly may be called the. pressure notch and isopen tothe lower edge of its plate by. means. of a cutout 51'! of a,width equal: to the. hole. diameter and somewhat tapered on its loweredges. so. that the. bar may be dropped: over the pin. 27. with facilityand-yet will have. close engagement therewith for one-half of theperiphery of. the opening drilled for the. pin. 21; Note that this match51 as viewed in. Fig. 2 faces. downwardly or in a directionnormal totheplane oft the doctor blade.

Thehole 58 at what may be. termed the front or tensioned end of." thesaddle. plate is connected to the lower edge thereof by means of acurved slot 59 directed first rearwardly from the opening. 58-as clearlyseen in Figs. 2 and 5, and then curving downwardly to exit through thebottom of the saddle plate. The forward portion of the saddle plate isof greater width than the rear to provide the hook end 60 beneath thepin 28 whereby a. flexing pull can beaimparted to the forward edge ofthe blade.

With the parts assembled as seen in- Fig. 2, it

is only necessary to loosen the tension screws 43 until the forward edgeof the doctor blade is well clear of the periphery-ofprintingroll [2.The blade assembly is then rotated about pins 21' until notches 51 arelifted off rear pins.,21. The whole assembly is then moved toward. theroll I2; and lifted to release the forward pins 28 from their openingsin the saddle plates. The doctor blade assembly is now wholly free fromthe machine and ready to be cleaned or otherwise conditioned for re-use.For re-assembly the operation just described is repeated in reverseorder, the hooks 60 first being moved beneath the pins 28 and the doctorblade assembly drawn rearwardly to seat the pins in the forward ends ofthe notches 59. The whole assembly is then rotated in a clockwisedirection as viewed in Fig. 2 until the notches 51 fit over the pins 21.The desired degree of flexing is then imparted to the doctor blade byappropriate adjustment of the tension screws 39 which rotate the arms 30in a counterclockwise iii) direction, carrying the blade with them untilit contacts the roll to the required degree of pressure.

The connection between each pin bar and its saddle plate is through apair of parallel pins and saddles so that the assembly of doctor bladeand shears is mounted for lateral vibration or oscillation such as maybe required in some cases to improve the operation of ink wiping.Mechanism for carrying out such oscillation is clearly shown in theprior patent to Frank F. Kaiser, 2,042,060, granted May 26, 1936.Because of the lengths of the pins 21 and 28 and the positioning of thesaddle bars in respect to the pin bars 24 room is provided for asubstantial amount of transverse movement of the doctor blade assemblyas will be appreciated from an inspection of Figs. 3 and 4. The pins andtheir saddle bar notches provide excellent guides which insure a truelongitudinal movement of the doctor blade under all circumstances andone which facilitates the application of the needed lubricant where suchoperation is desired.

The usefulness of the present invention will be readily appreciated whenit is seen that the doc- 6 tor blade. assembly can. be lifted. outvwithout the use of any tools. or the disconnecting, of; any assembledparts. i

I claim:

1. The combination with a. rotatable roll of a doctor blade having anedge for cooperation therewith, a pair of'pin blocks, one. adjacent eachend of the roll, means supporting. said blocks. for rotaryadjustmentabout an axis parallel: to that of the roll, individual.adjusting means for the blocks, two= spaced: pins; on. each blockparallel to the axis. thereof, a. saddle pl'ateirigidly. secured to eachend of; said blade. and spaced for cooperation with. saidtpins onsaidzblocks, each saddle plate having a. tension." hook-teengage the pinnearer the rolb and a pressure notch to rest on. the remote pin, alliengageable and disengageable. while the. blocks are in. position.

2. The combination of claim 1 in which. the pinsare of such lengththatthe-saddle plates may be oscillated longitudinally thereon to vibratethe blade.

3. The. combination. with a rotatable roll of a doctor blade. having. anedge for cooperation therewith, a. pair of blocks, one adjacent each endof: the roll, means supporting said: blocks for rotary adjustment aboutan axis parallel. to that of the roll, individual adjusting means. forthe blocks, each block having abutment means thereon extending towardthe other block, a: saddle plate rigidly secured to each end of" saidblade and spaced for cooperation. with said abutment means on said.blocks, each saddle plate having a tension hook to engage the abutmentmeans nearer the rollianda pressure area to reston the abutment meansremote from the roll, all engageable and disengageable while the blocksare in position.

4. The combination of claim 3 in which the abutment means have areasengageable by said saddle plate portions which are defined by elementsparallel to the roll axis and of such length that the blade may beoscillated longitudinally for the purpose defined.

5. In a doctor holder assembly, in combination,

rigid spaced side frames, parallel confronting end 1 plates supported bysaid frames, a pin bar fulcrumed on each plate for adjustment about anaxis connecting said plates, manual means for adjusting each bar aboutsaid axis, each bar having a pair of spaced pins projecting therefromtowards the opposite bar and parallel to said axis, a thin flexibledoctor blade, shear bars secured to the upper and lower faces of saidblade and leaving a portion of the width thereof exposed for flexing,one of said shear bars overhanging the ends of the blade and of theother bar, a

saddle plate for and secured to each of said overhanging bar portionsand spaced to respectively engage the pins on said pin bars, each ofsaid saddle plates having a tension slot parallel to the blade surfaceand a pressure slot substantially normal to that surface and eachopening through the bottom of the saddle plate for successive engagementwith the pins on a pin bar, the pressure slot being most remote from theexposed edge of the blade.

6. In a doctor holder assembly in combination, spaced side frames,plates supported by said frames, a bar fulcrumed on each plate forrotary adjustment about an axis normal to said plates, manual means foradjusting each bar about said axis, each bar having a pair of spacedpins projecting therefrom towards the opposite bar and paralle1 to saidaxis, a docter blade, shear bars pins on a pin bar, the pressure slotbeing most remote from the exposed edge of the blade.

7.-The doctor holder assembly of claim 6 in which the fulcrumed barseach have a lever arm secured thereto, and in which the manual adjustingmeans comprises a screw acting between the corresponding frame supportedplate and the end .of said lever to rock the bar for blade adjustment.

8. In a doctor holder assembly, in combination,

confronting rigid spaced end plates, a bar journalled on each plate foradjustment about an axis connecting said plates, screw means foradjusting each bar about said axis, each bar having one-half of a pairof interlocking means projecting therefrom towards the opposite bar andparallel to said axis, a doctor blade and shear assembly, the other halfof said interlocking means comprising a saddle plate for and secured toeach end of said assembly and spaced to respectively engage theinterlocking means on said bars,.ea'ch of said saddle plates having atension engagement area and a pressure engagement area forming part ofthe interlock and surfaces on each saddle'plate to hold the parts as- 8sembled for lift out separation: whereby the blade assembly may bequicklyremoved and replaced.

9. In a doctor holder for use with a roll mounted for rotation, incombination, confronting lplates supported adjacent the roll ends, a barfulcrumed on each plate for adjustment about an axis parallel to that ofthe roll, manual means for, adjusting, each bar about said. axis, eachbar having abutment means projecting therefrom towards the opposite barand having surfaces parallel to said axis, a flexible doctor blade,shears secured to said blade and leaving a portionof the width thereofexposed for flexing, a saddle plate for and secured to each end of saidbladeshear assembly and spacedto' respectively engage the said surfaceson said bars, each of said saddle plates having a tension slotsubstantially parallel to the blade surface and a pressure slotsubstantiallynormal to that surface and each opening through an edge ofthe saddle plate for engagement with the said surfaces on said bar,

the pressure slot being most remote from the eX-,

posed edge of the blade.

References Cited in the file of this patent UNITED STATES PATENTS

